Alma Walmsley

Related to https://github.com/Pyomo/pyomo/issues/3131 / https://github.com/Pyomo/pyomo/pull/3135. However, that indicates that this error should only occur when the legacy `__call__` method is used. For context, I am running into this issue with:...

Some feedback may be useful as I'm not sure if there are any implications on presolved values or other things I'm unaware of. My use case is "everything is defined",...

`pyomo/repn/plugins/ampl/ampl_.py` has the same exception in the `_print_model_NL` function (line 1365) ... should I look at adding the custom exception there as well?

This sounds good to me. To summarise: - Keep the empty model check for the old nl writer interface(s), but it should use an `EmptyModelError` - The new nl writer...

If I understand correctly, the new solver interface already has support for skipping a solve if it gets presolved? Something like this works: ```python from pyomo.environ import ConcreteModel, Var, Constraint...

Also, I think it doesn't necessarily make sense to limit the scope of this PR to just fixing the exception raised by the old nl writer. It is probably a...

I created the base exception `EmptyModelError` in `pyomo.common.errors`, and added this to the nl v1 and v2 writers. --- It seems that the LP and BAR writers (not sure about...

Fantastic, sounds good to me. I suppose I might as well join a dev call, assuming it is via something like zoom...? How should I get in touch with you?